The primary concern of this investigation is the consequential relationship of sickle cell anemia to sensorineural hearing loss and abnormal auditory function. The ultimate goal of this project is to investigate and define this relationship by determining the prevalence and predominate site of hearing loss and/or auditory dysfunction in sickle cell patients during sickle cell crisis, with the disease under control (non-crisis) and in the general sickle cell population. A comprehensive audiological evaluation process, including non-invasive auditory evoked responses and otacoustic emissions electrophysiological techniques will be utilized. Various investigators have assessed peripheral auditory sensitivity, with a wide disparity of results. A variety of case studies have documented middle ear, cochlear, VIII nerve, and central auditory involvement of sickle cell patients. Different patterns and degrees of hearing loss have been reported in association with sickle cell disease, ranging from profound losses bilaterally with partial recovery over time, to mild to moderate unilateral losses predominately in the high frequencies. Limited electrophysiological assessment of sickle cell patients has appeared in the literature. The specific aims of this proposal are: to investigate the relationship between sickle cell status (control versus crisis); site of auditory deficit (cochlea versus eighth nerve); and neurological/developmental consequences related to abnormal auditory function; to effectively define a paradigm predictive of significant auditory system deficits in relation to the number, duration and severity of crisis episodes; and to develop an economical and efficient model for appropriate audiological assessment and treatment of sickle cell anemia patients.